Catheter techniques are expanding into new territory, successfully aiding in the replacement of narrowed, calcified aortic valves in patients too sick to withstand open-chest surgery.
According to a study reported at the 30th Annual Scientific Sessions of the Society for Cardiovascular Angiography and Interventions (SCAI), May 9-12, 2007, in Orlando, FL, patients who were treated with the CoreValve Revalving System (CoreValve, Irvine, CA) experienced improvements in both the size of the aortic valve and in the severity of heart failure.
To evaluate the CoreValve system, Anita Asgar, M.D., and her colleagues at Montreal Heart Institute recruited 17 elderly patients with a severely narrowed aortic valve, all of whom had been turned down for surgery because of other health problems. In severe narrowing, or stenosis, of the aortic valve, the heart has difficulty pumping blood from the left ventricle to the rest of the body. The result is a back-up of fluid into the lungs and severe shortness of breath with even minimal activity.
With the CoreValve system, aortic valve replacement is performed by threading a special delivery catheter through the femoral artery in the groin and into the aorta in a direction opposite, or retrograde, to the normal flow of blood. Once the catheter is properly positioned in the opening of the aortic valve, it is pulled back to release the CoreValve, a self-expanding stent-like frame with the new tissue valve attached to its core. As it expands, the CoreValve covers the diseased natural valve leaflets.